U.S. patent application number 12/085520 was filed with the patent office on 2009-06-18 for method for supplying the electrical on-board power network of ships with external energy.
Invention is credited to Rainer Hartig, Hannes Schulze Horn, Kay Tigges.
Application Number | 20090152945 12/085520 |
Document ID | / |
Family ID | 38047505 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090152945 |
Kind Code |
A1 |
Hartig; Rainer ; et
al. |
June 18, 2009 |
Method for Supplying the Electrical On-Board Power Network of Ships
With External Energy
Abstract
A method is disclosed for supplying external energy to
electrical on-board power networks of ships, with there being at
least one generator, one converter and electrical loads in the
ship's on-board power network. In at least one embodiment of the
method, the converter (shore connection converter) on board the
ship, for transfer into the on-board power network, is fed by a
connectable external current source with current of a different
frequency and voltage to that of the on-board network and the
current is converted in the converter semiconductors into current
with the voltage, and the frequency of the on-board power network
and fed to the on-board power network.
Inventors: |
Hartig; Rainer; (Buxtehude,
DE) ; Horn; Hannes Schulze; (Gladbeck, DE) ;
Tigges; Kay; (Harsefeld, DE) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O.BOX 8910
RESTON
VA
20195
US
|
Family ID: |
38047505 |
Appl. No.: |
12/085520 |
Filed: |
November 27, 2006 |
PCT Filed: |
November 27, 2006 |
PCT NO: |
PCT/EP2006/068961 |
371 Date: |
June 13, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60740127 |
Nov 28, 2005 |
|
|
|
Current U.S.
Class: |
307/17 |
Current CPC
Class: |
H02J 2310/42 20200101;
B64D 2221/00 20130101; H02J 3/34 20130101; B63J 3/04 20130101; B63J
2003/043 20130101; H02J 2310/44 20200101; H02J 4/00 20130101; B63J
99/00 20130101 |
Class at
Publication: |
307/17 |
International
Class: |
H02J 3/00 20060101
H02J003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2005 |
DE |
10 2005 056 700.2 |
Claims
1. Method for supplying current to at least one electrical on-board
power networks of a ship including at least one generator, at least
one converter and electrical loads in the ship's on-board power
network, the method comprising: receiving at a shore connection
converter located on board the ship, for transfer into the at least
one electrical on-board power network and via a connectable
external current source on an input side, a current with a
frequency and a voltage differing from that of the at least one
electrical on-board power network; and converting the current in
the shore connection converter into current with a voltage and a
frequency of the at least one electrical on-board power network;
and supplying the converted current to the at least one electrical
on-board power network, wherein, in ships with an electrical drive
system, at least one converter of the drive system is used as the
shore connection converter.
2. Method as claimed in claim 1, wherein the ship's network of
control and regulating components is regulated on the output side
of the shore connection converter to a constant frequency and
voltage, which matches the momentary values of the at least one
electrical on-board power network at a moment when the external
current source is connected.
3. Method as claimed in claim 1, wherein, after the connection of
the external current source and until it is disconnected again, the
at least one electrical on-board power network and the external
current source continue to be operated with their designated
different voltages and frequencies.
4. Method as claimed in claim 1, wherein the shore connection
converter runs in four-quadrant mode.
5. Method as claimed in claim 1, wherein the shore connection
converter is regulated on the output side in such a way that, in
the case of changed performance requirements, which manifest
themselves in a tendency for the frequency to change, the power
output is adapted in such a way that the frequency remains
stable.
6. Method as claimed in claim 1, wherein control units and
regulating devices of the shore connection converter operate on a
software basis.
7. Method as claimed in claim 1, wherein a PWM converter is used as
the shore connection converter as the transfer converter for the
transfer of electrical energy.
8. Method as claimed in claim 1, wherein an intermediate circuit
converter having a static component in its regulation, is used as
the shore connection converter for the transfer of electrical
energy.
9. Method as claimed in claim 1, wherein, in the case of large
voltage differences between external current source and on-board
power network on the input side a transformer is connected between
the two.
10. Method as claimed in claim 1, wherein, in the case of
high-power shore connections, a plurality of feed cables run in
parallel are used.
11. Method as claimed in claim 1, wherein the ship with an
electrical drive system includes at least one of a cruise liner, a
large yacht and a military ship.
12. Method as claimed in claim 1, wherein, in the case of ships
with sets of shaft-driven alternators, the converter of the sets of
shaft-driven alternators is used as a shore connection
converter.
13. Method as claimed in claim 1, wherein, in the case of a
short-term failure or a disconnection of the external energy, the
on-board accumulators take over the emergency power supply via the
intermediate circuit of the shore connection converter.
14. Method as claimed in claim 2, wherein, after the connection of
the external current source and until it is disconnected again, the
at least one electrical on-board power network and the external
current source continue to be operated with their designated
different voltages and frequencies.
15. Method as claimed in claim 2, wherein the shore connection
converter runs in four-quadrant mode.
16. Method as claimed in claim 9, wherein the transformer is an
autotransformer with a plurality of voltage taps.
17. Method as claimed in claim 11, wherein, in the case of a
short-term failure or a disconnection of the external energy, the
on-board accumulators take over the emergency power supply via the
intermediate circuit of the shore connection converter.
18. Method as claimed in claim 1, wherein the at least one
converter of the drive system is a converter of at least one of a
propulsion motor, a booster and a thruster motor.
19. Method as claimed in claim 11, wherein the at least one
converter of the drive system is a converter of at least one of a
propulsion motor, a booster and a thruster motor 18.
20. Method as claimed in claim 17, wherein the at least one
converter of the drive system is a converter of at least one of a
propulsion motor, a booster and a thruster motor
Description
PRIORITY STATEMENT
[0001] This application is the national phase under 35 U.S.C.
.sctn. 371 of PCT International Application No. PCT/EP2006/068961
which has an International filing date of Nov. 27, 2006, which
designated the United States of America and which claims priority
on German patent application number 10 2005 056 700.2 filed Nov.
28, 2005, the entire contents of which are hereby incorporated
herein by reference.
FIELD
[0002] At least one embodiment of the invention relates to a method
for supplying the electrical on-board power network of ships with
external energy. In at least one embodiment, the on-board power
network of ships contains at least one generator, one converter
with control units and regulating devices and electrical loads.
BACKGROUND
[0003] The electrical equipment of a ship is known from WO
2004/028899 A1. In such cases this generally known electrical
equipment also has an energy generator, for example, a generator
for operation in port, which can be replaced by a shore connection
via a plug-in connection. If the shore connection is plugged-in, it
takes over the energy supply to the ship in port. Equivalent
procedures are also known from aviation.
[0004] To make it possible for the functions to be taken over from
the in-port generator by the shore connection, the shore connection
must supply current with the voltage and the frequency of the
on-board power network. However the disadvantage in such cases is
the fact that such shore connections have to be specifically
tailored (frequency and voltage) to the ship or aircraft to which
current is to be supplied, and because of this are not always
available. A suitable shore connection is usually only available at
a permanent mooring or at larger airports.
[0005] Therefore, on calling at foreign ports or on flying into
smaller airports, at least one in-port diesel generator set in the
case of a ship or gas turbine generator in the case of an airplane
continues to run for the duration of the stay. In such cases
exhaust gases and noise are continuously generated. Because this is
extremely annoying and pollutes the air, some port administrative
authorities now prohibit the operation of in-port generators on
ships.
[0006] In the case of aircraft, the passengers waiting on the apron
are inconvenienced to a considerable extent. The generator of the
aircraft is therefore only expected to operate for the shortest
possible period in time. Shore connections are likewise already
provided in some cases for yachts and also for passenger ships.
Likewise, many airports already have terrestrial cable connections,
which can be plugged-in accordingly. Even in the case of military
(navy) ships, corresponding restrictions are increasingly being
enforced.
SUMMARY
[0007] At least one embodiment of the invention specifies a method
for ships by which the shore energy can be transferred without
difficulties. In this case, the voltage and the frequency of the
shore energy should not have to conform to the on-board power
supply of the ship. However, according to an important subordinate
object of at least one embodiment of the invention, it should be
possible to carry out a load transfer without blackout during the
transfer and it should be possible to switch off the generators
located on board the ship without there being any disruptions in
the network.
[0008] At least one embodiment of the invention includes converter
(shore connection converter) found on board the ship, for transfer
into the on-board power supply, being fed on the input side by a
connectable external current source with current with a frequency
and a voltage differing from that of the on-board power supply and
by this being converted in the converter semiconductors into
current with the voltage and the frequency of the on-board power
network and fed to the on-board power network. This has the great
advantage of allowing external current sources to be used, the
voltage and frequency of which do not match the specific on-board
power network. The connection can thus be carried out in a very
advantageous manner without having to synchronize the on-board
power network to the shore network. The control and regulating
components of the shore connection converter simply cause said
converter to accept energy from the external current source and
convert the accepted energy into a current with the
on-board-specific voltage and frequency with a correct phase
relation.
[0009] This produces a previously unmatched flexibility in the
supply of external current at low cost because a converter with
on-board control and regulating components is present in any event
on modern ships. Its function is simply changed in port into a
shore connection converter. The monitoring devices present on the
on-board side can also continue to be used. Of particular advantage
is the fact that short-term voltage drops in the shore network,
which occur once in a while in ports, or also a temporary failure
of the external current source, which also occasionally occurs in
ports, cannot cause damage to the on-board electronics. The same
applies to overvoltage peaks. The shore connection converter can
compensate for short-duration voltage drops and overvoltage peaks.
Any existing low-voltage network or a medium-voltage network
available in the port can be used and is not subject to any
particular quality requirements.
[0010] In an embodiment of the invention provision is made for the
ship's network or the aircraft network of control and regulating
components to be regulated on the output side of the shore
connection converter to a constant (rigid) frequency and voltage,
which conforms to the momentary values of the on-board power
network at the moment when the external current source is
connected. Because of this, an interruption-free energy supply is
possible at the moment when the external energy source is
connected. The passengers will not notice the switchover from the
on-board power network to the shore connection supply and the
method avoids having to switch on the emergency lighting at the
moment when the external energy is transferred (a process which
frequently causes irritation). The details of the technical
implementation are as follows:
[0011] The generator regulator takes care of maintaining the
desired voltage of the on-board power network. The power management
takes care of the automatic control of the energy generating sets
such as switching on, switching off and load distribution.
[0012] The control and regulating components of the shore
connection converter must be expanded to function as suppliers of
current from the shore supply and must be included in the power
management system of the ship. In the control and regulating system
of the shore connection converter there must be a functional module
for the transfer of the on-board power supply by the converter, in
which case the on-board power network, at this point in time, is
controlled by the on-board power supply generators. Power
management then takes care of the load transfer to the shore
network via the converter and switches off the on-board power
supply generators. The on-board power supply is then controlled by
the control and regulating components of the converter. The
switchover from the shore connection to supply by the on-board
power supply generators is subsequently undertaken in the reverse
order. The switchovers must basically be carried out
interruption-free.
[0013] In a further advantageous embodiment of the invention,
provision is made for the fact that, after the external current
source is connected up to the time that it is disconnected again,
the on-board power supply and the external current source can
advantageously continue to be operated with their predetermined,
different voltages and frequencies! This makes the outside energy
supply particularly simple and it also runs without interruption.
Converters are designed for this type of operation.
[0014] In this case, of particular advantage is the fact that the
shore connection converter is in a position to compensate for
differences in the voltage and in the frequency during operation
within the framework of technical feasibility.
[0015] In addition, provision has been made for the fact that the
shore connection converter operates in four-quadrant mode. This
makes the converter behave in an especially favorable manner during
operation. In such cases it is also possible to couple different
phase sequences.
[0016] Furthermore provision has been made especially
advantageously for the shore connection converter to be controlled
and regulated on the output side in such a way that, should
performance requirements change, which is reflected in a tendency
for the frequency to change, the power consumption is adapted in
such a way that the frequency remains stable. Thus, for ships with
a plurality of generators and large loads, a stable network is
obtained in an especially advantageous manner even when the
generators or the large loads are disconnected or connected,
without there being voltage peaks or voltage drops. A stable
network is also obtained at the moment the load is transferred in
this way. The network instability which would otherwise frequently
occur when the generators or the large loads are disconnected or
connected, requiring regulation and control interventions by the
crew, is now no longer applicable. Overall the energy supply of a
ship with a plurality of generators and loads becomes considerably
more secure and manageable. The shore connection converter handles
some of the tasks which would previously have to have been handled
by the on-board team.
[0017] Provision is made in this case, in an embodiment of the
invention, for the control units and the regulating devices of the
shore connection converter to operate on a software basis. This
makes it possible for the shore connection converter to react
securely and quickly to different supply and consumption conditions
over a wide range. This means, that--guided by the frequency--the
shore connection converter ensures the stability of the network.
Changes in the load, which would otherwise manifest themselves as
frequency deviations, are regulated out immediately.
[0018] In an embodiment of the invention provision has been made
for a PWM converter to be used as the shore connection converter
for the transfer of electrical energy. An especially simple direct
conversion of the different voltages and frequencies to the
required voltage and frequency is possible.
[0019] In another embodiment of the invention provision has been
made for using an intermediate circuit converter, especially with a
static component in the control device, as the shore connection
converter for the transfer of electrical energy. Intermediate
circuit converters are already widely used.
[0020] In principle, an intermediate circuit converter can only
transfer active energy. An intermediate circuit converter has a
capacitor as an energy store in the intermediate circuit. A
self-driven power inverter for supplying the on-board power supply
with a voltage can shift these two away from one another in their
phase relation and in this way supply active components and
reactive components to the on-board power supply. Depending on the
dimensioning data, the power components of the converter can make
available an apparent power to the on-board power supply. The power
is thus limited by the apparent current of the converter. The
active component and the reactive component are set by the loads.
This also has to be taken into account when loads are
connected.
[0021] In addition provision has been made in an embodiment of the
invention, where there are large load differences between external
current source and on-board network, for connecting a transformer
on the input side, in particular an autotransformer with a
plurality of voltage taps. In this way, the load of the shore
connection converter can be relieved if required and also a ship
having only a low-voltage network can be supplied in a simple and
safe manner from an external current source with medium voltage,
for example up to 10 kV or vice versa.
[0022] In addition, provision has also been made according to at
least one embodiment of the invention, in the case of ships with an
electrical drive system, for example, cruise liners, large yachts
or military (navy) ships, for at least one converter of the drive
system (booster, propulsion motor or thruster motor) to be used as
the shore connection converter. In the case of ships, there is a
tendency for the power demand for the hotel services, for example,
for lighting, heating and cooling, to also increase because of
increasing demands for comfort. The above-mentioned converters thus
have a capacity reserve for implementing the invention, which will
continue to keep the costs for implementing the method low when
they are used in future.
[0023] In the case of container ships and for other ships which,
because of their sailing profile and their performance requirements
imposed on the electrical system, now frequently already have sets
of shaft-driven alternators, provision has also been made in an
advantageous manner for the converter of the sets of shaft-driven
alternators to be used as a shore connection converter. The
shaft-driven alternator system, like a booster system, is
dimensioned so that the on-board power network of the container
ship or other ships with sets of shaft-driven alternators can cope
with the higher requirements for generating electrical energy in
future. For example the number of refrigerated containers is
continuously increasing in the case of container ships.
[0024] In order to increase safety when transferring higher power,
it is advantageous to use more than one shore connection
terrestrial cable. This also makes the cables themselves lighter
and able to be handled more easily.
[0025] In addition, provision has been made, in the event of a
temporary failure or a disconnection of the external energy, for
the on-board accumulators to take over the power supply, at least
in part, and to be connected to the shore connection converter.
[0026] A sudden failure of the shore supply will result in a
short-term blackout in the on-board power network. The power
management takes care of starting up an emergency generator as well
as starting up the on-board power network generators. However, this
usually takes approximately 45 seconds. In this case, the energy of
the on-board batteries cannot then support the entire hotel load of
the on-board power network; the power required for this is too
high. The support is essentially only sufficient in order to shut
down the shore connection converter in a regulated manner, to
maintain the emergency lighting and to start the emergency
generator or the on-board power network generators.
[0027] Even with passenger ships there have been cases in recent
years in which all the generators on board said ship have failed
temporarily. A failure is in particular possible in the case of
military (navy) ships, which for example have been subjected to a
terror attack in port. In accordance with at least one embodiment
of the invention, a complete blackout, which would be associated
with the failure of the normal generator, can be avoided in this
case. In this way, the ship remains able to communicate and the
interior lighting can remain operative at an intensity which
considerably improves the repair work and the assessment of the
damage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Embodiments of the invention is described in greater detail
with reference to drawings, from which, in the same way as from the
subclaims, inventive features can also be taken. These drawings are
as follows:
[0029] FIG. 1 shows a schematic diagram of a typical ship with
inventive components of an embodiment on board;
[0030] FIG. 2 a schematic diagram of the most important parts
according to an embodiment of the invention using as an example a
ship with an electrical drive unit;
[0031] FIG. 3 a schematic diagram of the most important parts
according to an embodiment of the invention using as an example a
ship with a hybrid drive; and
[0032] FIG. 4 a diagram of the electrical structure of a suitable
converter.
DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
[0033] In FIG. 1, the number 1 refers to the schematic outline of a
ship and the number 2 to a medium voltage shore connection. A
voltage of up to 10 kV is specified for the shore connection. This
typically represents a medium-voltage network, which is frequently
available in ports. 3.3 or 6.6 kV could of course also be possible.
All voltages are possible here according to an embodiment of the
invention. By way of the cable indicated by the number 3 in the
diagram, a number of cables run in parallel can also be used for
this task in order to increase the safety and allow easier
handling, the electrical energy is fed into the plug-in connection
4 and is transferred from there to the ship's network 5. Frequently
a transformer 6 is also connected between the two in order to be
able to match the voltage of the ship's network 5 in an
advantageous manner for instance.
[0034] In addition, the diagram shows a typical converter 7 in the
ship, which is fed by one or more of the generators 8. In this
case, the generator or generators can either be generators of the
ship's drive train, sets of shaft-driven alternators, or the
generators of diesel generator sets, which have been distributed in
the ship. The propulsion motor of the ship 11 is for example
supplied with energy via the switchgears 9 and 10, which in the
case of modern container ships can be embodied as a booster/a set
of shaft-driven alternators. Not shown and not to be included in
considerations is a main diesel engine of the ship, if this is
present. However, even when using a main diesel engine as the
drive, there is usually at least one converter for at least one
generator. Should this not be the case, such a converter can easily
be retrofitted without any problems whatsoever. The retrofitting
can also include a plurality of smaller converters operating in
parallel. This is recommended if a number of feed cables are to be
used.
[0035] In FIG. 2 the number 12 refers to an embodiment of the
inventive shore connection converter used with its converter
control 13. 14 refers to the control and regulating system for the
ship drives with the driving lever 15. 16 refers to the control and
regulating system for controlling the on-board power supply and in
addition the shore connection. The power supply is designated with
a 17, it has its own voltage U, a frequency F and a phase relation
P and is connected to a circuit breaker on the shore side. With
these features, the current of the shore connection passes into the
shore connection cabinet 18 and is transferred from there via the
switch 19 to the shore connection converter 12.
[0036] The transformer which might advantageously be provided is
not shown in this diagram. In its place, the converter 12 has a
transformer 20, which together with the converter 12 and the motor
21 form the power train. Switches 22 and 23 complete the drive
diagram. Naturally switches 19 and 22 have been designed in such a
way that a simultaneous closing is impossible so that the motor 21
is safely prevented from starting while the shore connection 17 is
still engaged. (locking)
[0037] FIG. 3 shows a variation of FIG. 2. In this case, the
electrical propulsion motor M is replaced by an electrical
motor/generator device, which is preferably fitted to the propeller
shaft. Such hybrid systems in addition have a power management
system in which the generators shown in FIG. 1 or the additional
sets of diesel generators present on board large ships have, for
instance, also been included in this case in order to make possible
an optimum generation of electrical energy on board ships.
[0038] FIG. 4 shows a converter which is particularly suitable and
on the input side of which the voltage U1 is applied, whereas on
the other side, the voltage U2 is output. The converter, which is
shown in a conventional manner, has an intermediate circuit, in
which case both parts of the converter have an independent
regulator. In this way, it is possible to set the voltages and the
currents for the inventive power shown in the diagram. The
converter is identified by the number 24, whereas the converter
regulators are identified by the numbers 25 and 26. If required,
the converter also has an additional regulating facility, which if
required contains an additional static component. This additional
converter regulation is designated with a 27. It can carry out
reactive power compensation.
[0039] As has already been mentioned, the person skilled in the art
of converters is well aware of the technical design of such
converters, and the technical embodiment of such converters does
not form part of the subject matter of this invention. An installed
converter with known control units and regulating devices is
instead installed and adjusted in such a way that it processes the
shore network available on the input side and generates a current
on the output side in a stable manner, corresponding to the
on-board power supply conditions as regards voltage, frequency and
phase relation.
[0040] In principle, the method according to an embodiment of the
invention is also suitable for the power supply of aircraft in
airports. However, because aircraft currently do not work with
converters, but with special generators, they still do not have
suitable converters. In this case, a corresponding land connection
converter currently has to be retrofitted. However, equipping, in
particular, large aircraft with converter-fed on-board power
supplies is fully expected in the course of further technical
developments. Even though no express reference is made to aircraft,
embodiments of the invention are also intended to extend to such
aircraft.
[0041] Example embodiments being thus described, it will be obvious
that the same may be varied in many ways. Such variations are not
to be regarded as a departure from the spirit and scope of the
present invention, and all such modifications as would be obvious
to one skilled in the art are intended to be included within the
scope of the following claims.
* * * * *